Volkswagen told employees at its Chattanooga, Tenn., plant that it would “remain neutral” in the midst of an ongoing campaign from the United Auto Workers to unionize the facility, but the company also indicated that it’s made improvements for workers without a union.

Volkswagen Group of America President Scott Keogh touted an already “open dialogue” with plant workers that he said has resulted in wage increases and other changes. Keogh and Antonio Pinto, who runs the plant, said they believe “we can achieve more for us all by continuing that open dialogue directly.”

“We will respect our employees’ right to...